No group has yet said it carried out the attack
The blast was caused by a car bomb, an official has told the state-run news agency Mena. No group has yet said it carried out the attack.
The explosion on Saturday morning injured at least four people, according to medical sources.
Egypt?s public prosecutor, Hisham Barakat, was killed last month by a car bomb attack in the city.
In the same month, another car bomb targeting a police station left three people dead.
Egyptian security forces have been battling Islamic militants, but the fighting has been mostly confined to the Sinai Peninsula.
Militants in Egypt have killed at least 600 police and armed forces personnel in the past two years.
The militants stepped up their attacks after the military overthrew Islamist President Mohammed Morsi in July 2013.
In recent weeks, Egyptian President Abdul Fattah al-Sisi has promised to crack down further on Islamist militants.
Hundreds of Muslim Brotherhood members, including ousted President Mohammed Morsi, have been sentenced to death by Egypt?s courts.
The majority remain on death row awaiting execution.